The bored and stroked 261 might get up a little over 9:1 with an 848 head and flattop pistons. Have you looked inside a stovebolt combustion chamber lately? The recess for the exhaust valve could hold a little people's convention with some room left over. Why would you want more than 9:1 at the very maximum? Unless we're considering camshaft duration somewhere in the 290 degree range, there's no need for actual compression ratios over 9- - - -all it does is promotes massive detonation. The only reason for compression ratios in the 11-12 ballpark is to get the actual compression pressure back to where it once was when the intake valve actually closed near the bottom of the compression stroke. Getting the compression way up there without a corresponding increase in cam duration is a fool's mission. Stovebolt heads don't breathe well enough to benefit from long-duration cams, so why bother?
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!